Why cant i use the top up on my account to get a bundle?

[Roddi-13]

Im tryinhg to get a bundle on my O2 app by using my top up, but every time i ho and select the £10 bundle wich is the amount i topped up it asks me for my card details.

[Enlli]

Bundles can only be paid for via card. Top Ups are for anything outside of normal charges.

https://www.o2.co.uk/help/pay-as-you-go/big-bundles

[MI5]

@Roddi-13 

Sounds like you are on a rolling plan Pay As You Go: Introducing "Rolling Plans" 

Big bundles can be topped up from balance but rolling plans need a registered card.

If you wish to switch to a big bundle check if you can do it in your MyO2 or call O2 on 4445.

Guide: How to find help & contact O2